• Journal of Environmental Science International
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• v.22 no.11
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• pp.1457-1464
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• 2013

We investigated the optimal conditions for keratinase production by feather-degrading Pseudomonas geniculata H10 using one variable at a time (OVT) method. The optimal medium composition and cultural condition for keratinase production were determined to be glucose 0.15% (w/v), beef extract 0.08% (w/v), $KH_2PO_4$ 0.12% (w/v), $K_2HPO_4$ 0.02% (w/v), NaCl 0.07% (w/v), $MgSO_4{\cdot}7H_2O$ 0.03%, $MgCl_2{\cdot}6H_2O$ 0.04% along with initial pH 10 at 200 rpm and $25^{\circ}C$, respectively. The production yield of keratinase was 31.6 U/ml in an optimal condition, showing 4.6-fold higher than that in basal medium. The strain H10 also showed plant growth promoting activities. This strain had ammonification activity and produced indoleacetic acid (IAA), siderophore and a variety of hydrolytic enzymes such as protease, lipase and chitinase. Therefore, this study showed that P. geniculata H10 could be not only used to upgrade the nutritional value of feather wastes but also useful in situ biodegradation of feather wastes. Moreover, it is also a potential candidate for the development of biofertilizing agent applicable to crop plant soil.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.2_2
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• pp.425-435
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• 2024

The purpose of this study was to identify factors influencing learning satisfaction of nursing students in online non-face-to-face classes during COVID-19 pandemic. 138 undergraduate nursing students were recruited from C nursing colleges of C city in Gyungnam. Data was collected using a self-reported online-questionnaire from 5 January to 18 January, 2022. Collected data were analyzed by SPSS/WIN 27.0 program using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient, and multiple regression. Factor influencing learning satisfaction among undergraduate nursing students on online non-face-to-face classes during COVID-19 pandemic were teaching presence(presence of teacher)(𝛽=.43, p<.001), instructional quality(content qualities)(𝛽=.41, p<.001), Satisfaction of nursing major(satisfaction)(𝛽=.13, p<.001). instructional quality(interface)(𝛽=.12, p=.036), which explained about 85.3% of total variance(F=192.78, p<.001). Therefore, in order to improve class satisfaction in online non-face-to-face classes, it is necessary to operate classes that prioritize the presence of teacher so that learners can recognize and trust the presence of teacher by passionately professional performing. And, among instructional quality, we should be strengthen the usefulness of learning materials, content factors related to tests and assignments, and strive to improve satisfaction of nursing major. In addition, it is necessary to prepare and operate classes that fully consider the interface factors related to the manual composition and system convenience for online classes among the quality factors of classes.

• The KIPS Transactions:PartC
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• v.13C no.4 s.107
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• pp.389-396
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• 2006

P2P(Peer To Peer) system, a most attractive file sharing system, is the largest channel of contents distribution and it takes 50% of network traffic. But P2P systems are infamous for used to illegal contents distribution channel not only in music industry, but also in movie industry. But, DRM(Digital Right Management) enabled P2P models are not suggested until now that interrupting illegal contents distribution and keeping advantage of P2P. So in this paper, we suggest a DRM enabled P2P model that can support distributed processing ability and high scalability with no modification in exist P2P model or architecture.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.1
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• pp.17-27
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• 2017

This study evaluated the performance of bedding fabrics consisting of warp (150d/144f, polyester) and weft (polyester, Tencel and cotton MVS blended spun yarn) with blend ratio of weft. We measured electrostatic propensity, moisture properties, pilling properties and mechanical properties of the fabrics for this study. F-P fabric showed outstanding moisture properties and pilling properties. However, tensile properties and electrostatic propensity were relatively inferior to other characteristic values. Significant static electricity may make F-P fabric uncomfortable. F-P7C3 fabric showed outstanding moisture properties and pilling properties. Static electricity may make F-P7C3 fabric uncomfortable; in addition, F-P5C5 fabric showed outstanding moisture properties and pilling properties. Rough and stiff hand feel were expected to increase because tensile properties decreased and surface properties increased. F-C fabric showed outstanding pilling properties and electrostatic propensity. However, it showed inferior moisture control properties. F-P5T4C1 fabric showed outstanding moisture properties, pilling properties and electrostatic propensity. Several properties are outstanding; however, the hand feels are very rough and stiff from bending. The water evaporation and static electricity increased with increasing polyester content. As the content of cotton increased, tensile properties were improved. However, water evaporation and static electricity decreased. The addition of Tencel increased the thickness and compression energy so that it exhibited a soft characteristic upon compression and an excellent moisture control properties, but the surface became somewhat coarse.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.5
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• pp.27-33
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• 2011

Hemp bast pulp cooked at temperature below $100^{\circ}C$ followed by defibration by the knife and the valley beater, respectively was mixed with softwood pulp varying the amount of hemp pulp in order to find the optimum condition for making hemp-wood paper. Both the knife and the valley beaters contributed to the dispersion of pulp fiber well. Lots of shives were found when the knife beater was applied exclusively, but the fibers were dispersed well when freeness dropped to 600 mL CSF and 500 mL CSF by the valley beater. Air resistance decreased drastically below 500 mL CSF where rapid disrupture of pulp fiber occurred. As the values for freeness and hemp fiber content increased, so did roughness and bulk. It was apparent that the tear strength of hemp-wood paper was on the rise drastically as hemp fiber content increased. Nevertheless the optimum hemp fiber content of hemp-wood paper would be 20% considering the decrease in both tensile and burst strengths as well as sheet formation.

• Journal of the Korean Applied Science and Technology
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• v.25 no.4
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• pp.418-428
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• 2008

Transesterification of fat of Tra catfish with methanol in the presence of the KOH catalyst yields fatty acid methyl esters (FAME) and glycerol (GL). The effects of the reaction temperature and reaction time on rate constants and kinetic order were investigated. Three regions were observed. In the initial stage, the immiscibility of the Tra fat and methanol limited the reaction rate, hence this region was controlled by the mass transfer. Subsequent to this region, produced FAME like a co-solvent made the reaction mixture homogeneous, therefore the conversion rate increased rapidly so it was controlled by the kinetic parameters of the reaction until the equilibrium was approached in the final slow region. A second-order kinetic mechanism was proposed involving second regions for the forward reaction. The rate determining step for the overall KOH catalyzed-methanolysis of Tra fat was the conversion of triglycerides (TG) to diglycerides (DG). This rate constant was increased from 0.003 to $0.019min^{-1}$ when the reaction temperature was increased from 35 to $60^{\circ}C$. Its calculated activation energy was 14.379 ($kcal.mol^{-1}$).

• Journal of the Korean Society of Industry Convergence
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• v.22 no.2
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• pp.105-110
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• 2019

Most titanium alloy waste with cutting oil was discarded without recycling process so that it can be caused by metal and oil fires. However, there is no fire management system and studies on the titanium or titanium alloy waste in spite of high fire risk. The purpose of this experimental study is to identify the fire risk of the titanium alloy waste with cutting oil. We collected the 120g waste which was made in the biomedical titanium alloy cutting process. The waste was burned and conducted thermal image analysis with infrared camera. The experimental results which illustrated the process, characteristics, and trends of fire are presented. Firstly, the cutting oil was burned and partially the titanium alloy waste was burned. The maximum temperature of the fire was more than $650^{\circ}C$ in some specific spots. These results means when a lot of titanium alloy waste with cutting oil was ignited, this fire could connect the titanium fire. In other words, the fire has a flammable liquid fire and combustible metal fire at the same time. The experimental study could be used fire prevention, response, and investigation of the titanium alloy waste.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.1
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• pp.9-16
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• 2009

This study investigated vegetable buying behavior with the subjects of 250 housewives living in Gyeongju. According to the results, they usually buy the following vegetables by order of frequency: cucumbers (152 times), hot peppers (142 times), lettuce (140 times), and spinach (134 times). The intake frequency of fresh vegetables was 2 to 3 times per week as 50.0% responded so. All respondents considered freshness most importantly when buying vegetables regardless of age. They usually buy vegetables at traditional markets, and they think the markets are suitable for buying fresh vegetables regardless of age. And the result of analyzing relation among vegetable's vitamin C and the colors or kinds of vegetables selected by age was not statistically significant. About the improvements to use vegetables, respondents in the 20's chose useful information, ones in the 30's to 40's said diverse recipes, ones in the 50's went for the quality improvement, and ones in the 60's or more emphasized stable prices. They answered that they received nutrition information of vegetables mainly from TV or magazines, newspapers, and mass media whereas subjects in the 60's or more said they got it from neighbors or friends. For housewives to get and practice nutritional knowledge, it is necessary to develop recipes in consideration of nutritional balance and convenience and provide them with constant education of nutrition through lifelong education facilities.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.4_2
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• pp.701-708
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• 2020

In this paper, we analyzed the optical properties of the LED module for dental care, which has the effect of promoting cell regeneration and scar treatment. The LED module is a U-shaped module suitable for the shape of teeth. It is manufactured with an LED module (632 nm) and an LED module (632 nm + 870 nm), analyzes the results of optical properties, sets the irradiation distance, irradiation time, and is effective in healing skin wounds. Evaluation was conducted. It was tested in 6 test groups according to the light irradiation conditions, and light was irradiated to the scar site every other day for 7 days, 1 day and 3 days. As a result, it was confirmed that the effect of scar treatment was the highest when the combined wavelength of 632 nm + 870 nm was irradiated in pulse mode than when the single wavelength was irradiated and the composite wavelength was continuously irradiated. In group C group irradiated with PW Mode: pulse mode (period 36 ms, pulse width 35 ms) using a composite wavelength with LED module (632 nm + 870 nm) than group A without light irradiation, the length of scar reduction was 19 %, the area of the scar was further reduced by 10%, and it was confirmed that it is effective in treating scars in the wound area.

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.140-143
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• 2001

As global trade system transferred GATT into WTO, the harmonization of technological standards, certification, construction, testing is the trend of world. This drift is based on WTO / TBT agreement coming. In effect after 12th, April, 1979. For Korea, the distribution system has a strong resemblance to American system so that engineers are confused in adopting standards. IEC60364 and NEC are in part similar but unconvertible because IEC 60364 originated from Europe while NEC originated from USA. This thesis deals with the fundamental elements of electrical safety system with comparing IEC 60364 with NEC. It serves as a guide how to apply standards when engineers select electrical installations.